Developing an emulsifier system to improve the bioaccessibility of carotenoids

Food emulsion designs, with the aim of delivering lipophilic bioactive compounds, should include an estimate of their bioaccessibility to support the claimed effect. With this goal in mind, in vitro digestion models and experimental design of mixtures were used as analytical tools to measure this parameter and to optimize the formulation of an O/W emulsion, including carotenoids as functional ingredients. Two experimental stages were applied. First, a screening phase was completed to detect the critical factors that exerted a significant effect on the response (bioaccessibility). During this phase, we observed that the response was modified mainly by secondary effects such as synergies and antagonisms of the emulsifying mixture. A group of four emulsifiers was selected at this phase to perform the second experimental stage, the optimization phase. This allowed us to obtain the mixture that produced the maximum carotenoid bioaccessibility. This formulation had emulsifying properties of the liposugars, acyl- and polyacyl-glycerides, as well as the synergistic effect arising from the combination of materials; this maximized the response. The analytical approach applied in this work is of interest for food designers for screening and controlling the bioaccessibility of bioactive compounds in a given matrix and, consequently, selecting the formulation conditions for higher bioaccessibilities.